High intensity fluorescent lamp system



May 4, 1943. w. c. HALL, JR 2,318,072

HIGH INTENSITY FLUORESCENT LAMP SYSTEM Filed sept. 24, 1941 Patented May4, .1943

man .nv'raNsrrrYgnUonsscaNr Willard C. Hall, Jr., Los Angeles, Calif.,assgnor to Alfred P. Daniels, Los Angeles, Calif.

Application September 2i, 1941, Serial No. 412,124

6 Claims.

This invention relates to a system for safely increasing theilluminosity of gaseous electric discharge lamps and the like. Itisespecially useful forintensifying the illumnosity of fluorescent typelamps having end electrodes or cathodes which are heated to increase theflow of electrons. At present, the cathodes of such tubular. lampsoperate at a given current density which forms a single hot or glowspot; the character and heat of this spot largely determining the lifeof the lamp. ,Should more than the rated current pass through thecathode, the hot spot thereof becomes too intenseiand the filamentrapidly deteriorates and breaks.

This'invention intensifies the illuminationof standard gaseous electricdischarge types of lamps by forming a plurality of hot or glow spots onthe cathodes. By forming a plurality of hot 'nating device and thecharacter 2, the transspots, each hot spot does not become overheatedand the lament, therefore, does not rapidly deterlorate thus eachlcathode safely operates at greater electronic capacity.

This invention intensies the illumination of standard gaseous electricdischarge types of4 lamps y by forming a plurality of hot or glow spotson the cathodes. The hot spots do not tend to merge and the lament isnot in any way impaired. Instead of the lamp having al1 its lightingenergy emanating from a single spot upon the cathode, a plurality ofsuch spots supply the energy at a low temperature and forms a greatercolumn of light giving properties throughout the active length of thelamp. An object of this invention is to present an electrical system forgreatly increasing the illumination of gaseous electric discharge lampswithout shortening the useful life thereof.

Another object is the provision of a transformer device which is capableof forming a plurality of hot spots on a single cathode.

Still another object is to provide an electrical system for standardgaseous electric discharge lamps which forms a plurality of hot spots ontheir laments for materially increasing the einciency thereof at a highpower factor; this being accomplished by a simple sturdy deviceeconomical to manufacture.

Other objects. advantages and features of my invention will appear fromthe accompanying drawing, the subjoined detailed description, the

preamble of these specications and the appended claims.

Applicant is about to illustrate and describe one of the forms of hisinvention in order to teach one how to make, use and vend the same, butit is to be understood that the drawing and description thereofare notto limit the invention in any sense whatsoever, except as limited by theappended claims.

In the' drawing:

Fig. l shows a wiring diagram of the invention.

Fig..2 shows in elevational view, parts being' broken away, of a switchadapted lfor use in the invention. y

,The reference character t indicates the illumisformer. The illuminatingdevice in the drawing is a glass tube or envelope having at its ends theglass presses 3 and through which pass the conductors 5 and E, and theconductors l and 8 respectively. Within the envelope are the electrodesor thermionic cathodes 9 and l0 in the `form of coiled filaments havingtheir ends connected across the lead in conductors at their respectiveends of the tube. The tube is lled with nated limbs, a large'areacentral limb Il upon tov and the other end to conductor 1. Shunting thecoil Il are the switchA 2l having leadsl2l' and 2|" and the condenser 22with its leads 22' and 22". The other secondary coil has one endconnected to the conductor 6 which leads to the cathods 9, and the otherend of which that connects with the conductor 8;-the conductor 8 leadingto the other cathode I0.

The instantaneous polarity of the'secondary coils are indicated, and'show that the instantaneous positive polarity of each coil is connectedacross one of the electrodes and the instantaneous negative polarity ofeach coil is connected across the'other electrode. Therefore, when analternating current; for instance,

at an impressed line voltage of and frequencyof 60 cycles, is connectedto the primary l2 through switch I4', like voltages and polarity, at anygiven instant, is impressed across one of the electrodes, and theVopposite polarity across the other electrode. 'I'his is the case whenthe tube is in 'normal operation by electronic bombardment. Y

To start the tube, the switch 2l and condenser 22 must function so as toilrst heat the cathodes and provide the higher voltage surge to strikethe tube. The switch 2l may be ofthe gaseous electric discharge type nowto be described, or it may be of the type that is closed when cold andopen when hot. Y

In Fig. 2 of the drawing, a gaseous electric dis charge switch is shownwhich is especially adapted for use in this invention. lI'he switch hasa casing or envelope 2l which may be of glass or metal, and has theglass press or seal 28 which give support to the two bixnetal strips 29and 30, the strips having connection with the wire conductors 2|' and2i" as shown in Fig. l. One of the strips has a curled contactor 3| andthe other strip has a plate contact/or 32. The envelope is iilled withany suitable ionizable gas such as neon. When current at proper voltageis connected across the leads of the switch, an electric discharge willtake place between -the strips 29 and 30 and heat them. Upon heating,

the strips will flex toward each other and their ends make contact toclose the circuit; contacti havingbeen made, the switch strips 2S and 30cool and separate and thus open the circuit to which they are connected.This switch when closed, at the start of operations, short circuits thecoil I1 and thus doubles the power out-put and voltage of coil i8 whichis then in series with both electrodes and provides the current to heatthese electrodes. When the laments of these electrodes become hot, theswitch 2| automatically opens (a matter of a few seconds) and connectslike polarity ends of both coils to their reu spective electrodes.Immediately, the electrodes have opposite polarity at any instant, andare maintained at operating heat by electronic bombar'dment alone.

By the arrangement of this new system, two

- hot spotsform on each electrode at their ends as indicated by thenumerals 23, 24, 25 and 2B. `These spots form conductive gas columns inthe tube which merge to form an intensified prin-4 ciple conductivecolumn which extends themajor length'of the tube. The spots on eachelectrode do not tend to unite due to the resistance along the lamentbeing greater than the ionized gas column. 'Ihis action means that it ispossible-to run the tube at twice its normal current capacity and henceobtain nearly twice its nor- 2,s1s,o7a

1. In combination, a gaseous electric discharge lamp with end cathodesand a transformer, the

. transformer having a primary coil, and secondary windingssubstantiallyin phase with theirv like polarity ends connecting acrossone cathode and the other opposite like polarity ends connected acrossthe other cathode, and switch means connected across one of the windingsto short it when the lamp is started. i

2. In combination, a, gaseous electric discharge lamp with end cathodesand aitransformer, the transformer having windings substantially inphase with their like polarity ends connecting across one cathode andtheir other opposite like polarity ends connected across the othercathode, a switch and condenser having leads connecting opposite ends ofone of the windings, the switch operating to short the winding whenclosed, and

a primary coil for energizing they windings. l

3. In combination, a gaseous electric discharge lamp with end electrodesand a transformer, a primary winding for supplying power to thetransformer, a pluralityof secondary coils, the ends of the coils havinglike polarity connecting across one of the electrodes and the other endsof the coils connecting across the other electrode, switch means forshort. circuiting one of the-coils to allow the other coil to heat theelectrodes in series.

4. In combination, a, gaseous electric discharge lamp wih end cathodesand a transformer having three limbs, a'primary winding on one of thelimbs having connection to a source of electric current, a secondarycoil on each of the other two limbs, a conductor from one end of eachcoil connected across one of the cathodes and another-conductor from theopposite end o1 each coilconnected across the other cathode, a switchconnected across one of the coils for the purposes described.

5. The method of forming a plurality of hot spotson the cathodes oi' agaseous electric disi charge lamp by: providing across each cathode malbrilliancy without injury to the cathodes or i a like instantaneouspolar voltage and maintaining the cathodes in opposite 'instantaneouspolarities with respect to each athen-and maintaining the spots on thecathodes separated by maintaining a lower resistance between thecathodes then between the spots.

6. In combination, a gaseous electric discharge lamp with a plurality ofelectrodes and a transformer having a primary coil and4 secondarywindings, two of the electrodes each including a filament having spacedapart'hot spots, one of the filaments having its ends connected acrosslike polarity parts of said windings and the other filament having itsends connected across the opposite like polarity parts of the windings,and switch means connected across one of the windings to short it whenthe lamp is started, the shorting of said one of the windings connectingthe other winding in series with said filaments.

.wILLARp c. HALL. JR.

